A device which controls the voltage and current being delivered to a capacitor or battery.

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-5
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0answers
34 views

unknown amperage charger problem? [closed]

Ok, so here's the thing. Our dell inspiron n7010 charger died (19.5v 4.62A, 90w), and we managed to get our hands onto some universal charger, which claims to give 120w and an array of voltages from ...
1
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1answer
50 views

Charging 7.4V Li-Ion battery

I'm making a battery out of two 3.75V Li-Ion cells to go into a speaker system that powers an amplifier. I was wondering on the PCM, how many volts would be max to charge these cells? The cells I have ...
0
votes
1answer
21 views

ICSwitching between solar panel and batteries

I would like to charge the NiMH batteries, when there is excess power from the solar power and use the power stored in the batteries, when I need it (to drive a motor and at night). I have the ...
0
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2answers
56 views

What are the downsides of using a LM7805 with a 11.1v Li Ion Laptop battery to charge a USB device?

I want to use my thinkpad battery(11.1v) hooked up to a LM7805 to charge a USB Device. What are the downsides to such a setup?
0
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1answer
51 views

Charging 2 Li-Ion Batteries via a single charger

I'm currently building a portable USB charger. It uses 2 Li-ion batteries in series connected to a USB port via a 5V regulated buck converter. While a single Li-ion battery would suffice for most ...
0
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1answer
41 views

What does 'Braked Voltage' mean on a charge controller?

Here is the complete specs of the controller. Battery rated voltage: 12v Wind turbine rated power: 300w Wind turbine braked voltage: 15v Recover voltage: 13.5v Quiescent dissipation: <8ma ...
0
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1answer
54 views

POWER SUPPLY / CHARGER [duplicate]

I have a 14.4v NI CD power drill with a charger that outputs 18v 400mA (original charger for drill) but the charger supply lead no longer works. Looking to get a replacement but finding it difficult ...
0
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1answer
69 views

Charging of Cell Phone Batteries and Electricity! [closed]

Does charging an already charged battery of cell phones/laptops consume electricity? Whenever my cell phone becomes fully charged while charging, it asks me to remove the charger from the socket to ...
0
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1answer
91 views

Multi port usb charger

I want to make a multi port usb "dumb hub" kind of like this. My question though is if I have a 5v 2500mA power supply, can I just daisy chain them together with out the fuses then connect it to the ...
1
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2answers
48 views

Need to charge a lithium power pack from USB

I need to charge a small lithium power pack from a device that was originally charged using a 5v USB connection. The connector on the device is damaged so I need to charge the power pack directly. ...
0
votes
1answer
90 views

Powering circuit from 12V with stand-by battery + solar charger

I did some research but I haven't been able to find the information that I really want. I am building a home made security system consisting of several IP cameras. Brownouts are very frequent so I ...
-2
votes
1answer
63 views

humming of a mobile phone charger [closed]

Why do a mobile phone charger (without mobile phone attached to it) constantly hums when kept plugged into A.C. outlet and the moment mobile phone is plugged into charger, humming goes. Why so ?
5
votes
3answers
697 views

How to make a voltage multiplier of 1.075

I have an 80v power supply that's rated to put out 18 amps, and I'm planning on using it to charge an 80v battery pack. Unfortunately the pack's charge voltage is 86v, so what I'm wandering about is ...
0
votes
1answer
74 views

How can I disconnect a Battery Charger from the Battery while not Charging

I have a LiIon Battery Charger IC which will draw around 50µA when not needed, see circuit 1. This is a lot of current for no work in my opinion. Now I search for a solution how I can disconnect the ...
1
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0answers
50 views

Why does the QI charger I recently bought only charge for a couple of times? [closed]

I recently bought a QI compatible charger for my Nexus 5. On the box it states, that the wireless charges up to 500 times. I don't understand why the charger is only able to charge my phone 500 times. ...
3
votes
2answers
87 views

What might cause audible noise in an inductive charging system?

I have a pair of Qi-compatible wireless charging pads, and I've noticed that when a device is charging, the pad will emit a quiet but noticeable squeal in a relatively high frequency range. Perhaps ...
3
votes
1answer
85 views

How do I smooth current dips on a USB charger?

I've got a USB charger that I want to use to charge a phone. For about 35 seconds it outputs enough current for the phone to detect it and start charging, then for an instant (no equipment to read ...
4
votes
2answers
154 views

Hacking wall wart as a USB charging station

I would like to modify an old power supply to have a USB A female adapter so that I could use it to charge any device. I plan to split out the power lines from an adapter that is: Input: 100-240V - ...
1
vote
1answer
91 views

Modding a charger into a power supply + charger?

I am making a handheld radio telescope which needs 13-18v to power and currently runs off 2 9V batteries. However it eats power like mad, drains them so hard that it actually needs to be recalibrated ...
1
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2answers
186 views

Can I use a 0.7A charger in place of a 1A charger? [closed]

One problem that I usually come across is the current ratings on mobile phone chargers. Right now, I need a 1A charger (which was shipped with my phone) and I have a 0.7A charger handy. Both the ...
1
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3answers
194 views

How safe is this?

I'm wondering how safe this is to make and to build into my setup. :P A bit afraid of it exploding. http://www.apartmenttherapy.com/make-your-own-batterypowered-u-100359
1
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2answers
149 views

powering +5v device with usb and/or battery

I made a PCB with an arduino clone and a tiny motor driver. The arduino clone itself needs +5 volt power supply, so I decided to use a DC/DC boost converter to boost a 3.7 volt Li-Ion battery to +5 ...
0
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0answers
43 views

Li-ion and Li-po charger current leak from input pin

According to the block diagram below of TI BQ24074 Li-ion/Li-po charger, could some current (even tiny) leak from BAT/OUT to IN when IN is disconnected from its source ? I noticed the Q1 transistor ...
1
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1answer
248 views

Emulating a USB Standard Downstream Port Charging application

I have am using an LM5017 to step down a relatively high voltage solar panel (VOC over 90V) to 5V. I have bench tested my circuit and it is providing good buck regulation with input voltages up to ...
1
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1answer
44 views

Looking for some solar panels to go with this project

I've been looking around for some solar panels for a little homemade solar phone charger project. I recently found a portable phone charger project from a student at Cal Poly which I'm hoping I can ...
1
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2answers
91 views

Combined chip with LDO and Buck, what use?

I am searching for a Li-polymer 1A charger with a 3V regulated output. I have found Linear LTC355x serie but can't, after reading many "LDO vs Switching" debates, understand the use of both on the ...
4
votes
4answers
253 views

Charging phone battery with a high current source

I am working on a project which the goal is using some android tablets to show pieces of video file to form a multiscreen. One electronic problem that I have faced is: The tablets should be always ...
1
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3answers
218 views

Charging batteries directly from 117 volt wall socket

It has occurred to me that almost no battery charger would be required if the battery pack was of the same voltage as grid supplied power. I build electric bikes, and the voltage on these has been ...
1
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0answers
135 views

LEDs dim when using LM317 [closed]

I'm trying to construct a very simple emergency light system, but when I create the path represented by the red path in the image bellow, the LEDs lose brightness. Without this path I get 3.5v (with ...
1
vote
3answers
106 views

Using the Maxim MAX1873

Here is a schematic of the "Typical Application" for the Maxim MAX1873 - Can anyone tell me what "To system load" means? Does it mean I can connect this to let's say a 12V door lock (my input is ...
0
votes
1answer
102 views

li-ion battery charging

I'm trying to build a battery backup system for a door lock. I'm using the LTC4353 voltage monitor and switch that switches between the battery and a regulated DC supply depending on the AC mains ...
1
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1answer
151 views

Can I use the output of mobile charger as a DC source for my circuit?

The title explains it all. Can I use the voltage and ground pins from the mobile charger and use it in my breadboard circuit? Is it safe? If it isn't, what is the thing I need to buy so as to convert ...
0
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1answer
75 views

Charging a Large Li-Po Cell

Can someone suggest an IC or Circuit to charge a single high-capacity Li-Po Cell? I need some design that can charge powerful Li-Po batteries (think ~6000mah 1S 65~130C) at a reasonable rate (say ...
2
votes
1answer
678 views

How does my phone get charged via laptop USB port at lesser current (compared to wall charger) [duplicate]

Today's typical smartphone chargers are rated at 5 Volt & 1+ Ampere. The laptop USB can supply 500mA 100mA. Why is it safe to charge the phone with 1/2 the rated current? Is it like a slow ...
2
votes
1answer
430 views

Can a more powerful charger burn something? [duplicate]

I am told that I must use 5V, 1A charger to charge power bank. If I will use 5V, 2A charger then will it burn power bank? Is that possible? \$I = V / R\$ Charger give constant voltage and current ...
0
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0answers
41 views

What to replace for tx9013 in a mobile charger circuit?

I am looking to implement an circuit called emergency mobile charger. Yes it converts 1.5V from a simple AA battery to a 5.1V output regulated by Zener diode. I am a bit confused that will the circuit ...
0
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2answers
97 views

Full Charge Indicator

Can someone explain or give an outline of how the indicators on chargers work? I have a charger for a device, which displays a red light when connected and not fully charged, but after it is charged ...
3
votes
1answer
370 views

Why is earth pin absent in phone chargers plugs but present in laptop ac plugs?

Both mobile phones and laptop get dc voltage from ac source for charging.These chargers have transformer for isolation and rectifier + filter if i am not wrong.I guess the amount of output dc and ...
1
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1answer
137 views

How to use a solar panel that has 'watts' to power a battery charger that requires: 3v & 2.8 amps?

I have a battery charger that charges small batteries ( AAA & AA ). It uses an adapter that gives it 3V and 2.8 amps. I want to remove the adapter and give it solar energy instead. There are ...
0
votes
2answers
207 views

Resistor power rating needed

Top graph: voltage drop across the resistor vs. time Bottom graph: current through resistor vs. time This is a resistor charging a capacitor. If the cap is being charged and discharged 2 times a ...
0
votes
1answer
68 views

Can I charge multiple identical devices in parallel from on transformer

I have four identical devices (HDD enclosures), each requiring 12V, 2000mA. Each of them came with their own power supply/DC transformer, but they are fat and chunky, and if possible I'd like to ...
0
votes
1answer
132 views

dual stage charger, is fuse needed?

I have a basic circuit: battery, fuse off (+)lead, 4 lights in parallel. My question is, when charging is a fuse needed? Also in the battery/charger circuit, which side is considered positive? ...
2
votes
2answers
2k views

Using a 12V battery while simultaneously charging via solar panel

I have a couple of 12v batteries that I'd like to use to power a cooling apparatus while camping for several days. I also have a 15W solar panel I'd like to use to top-off the battery. Can I use the ...
0
votes
0answers
123 views

Simple 5v switching regulator circuit

I am trying to build a circuit to charge a couple of USB devices from the 12 volts from a car, but being a total newbie, I'm having a bit of difficulty understanding what to do with the switching ...
1
vote
0answers
167 views

Solar Powered MintyBoost

I've decided to try and make a Solar Powered MintyBoost. I've drawn up a very rough version of a schematic: As you can see, I plan to use a solar cell to charge a set of 2 D batteries (in series), ...
2
votes
2answers
131 views

Make a Solar Powered USB Charger

I'd like to make a solar powered USB charger, to charge my phone. I'd ideally like to use (a) solar panel(s) that I can 'mount' onto a canvas messenger bag, and use a pocket to hold my phone. ...
2
votes
1answer
238 views

Can someone clarify how to charge a battery without an off-the-shelf battery charger?

I am a college sophomore studying EE, I am currently working on making a simple battery charger circuit for an integrated device. The device has 3 Li-Ion batteries in series for my motors, and a ...
0
votes
1answer
101 views

Adding AC adapter to solar powered device

I have a solar-powered LED number display whose rechargeable batteries have apparently died. I'd like to hook it up to AC power using a 3V adapter (i.e., cutting the leads from the batteries and ...
2
votes
2answers
345 views

Arduino project, powered by car electric system

I want to assemble an Arduino project that would be powered by car, and also it should be power-independent to some degree. This project will be a simple car alarm system, with gps reciever and will ...
2
votes
2answers
75 views

charge extraction from solar cells in low light conditions

This is probably not that deep a question, but how can one extract power from panels in low light? A 6V panel would dip to ~2V or so, and power output would sink lower. In conventional systems, how is ...